Assessment of Roundup Ready 2 (RR2) corn subjected to application of isolated and associated herbicides

Abstract

One of the first transgenic traits that has been inserted into commercial crops and being widely used is tolerance to glyphosate herbicide. This technology has provided significant benefits and conveniences to farmers due to the efficacy of glyphosate. However, for a better weed control and prevention of weed resistant biotypes the use of two or more mechanisms is recommended practice. The combination of herbicides is the subject of several studies especially evaluating weed control, aside which the selectivity of the culture is equally important. In this context, this study aimed to evaluate the responses of transgenic corn (RR2) subjected to the application of different herbicides. For this purpose, an experiment was conducted with eight treatments using glyphosate, atrazine and nicosulfuron, sole or in combination along with a control treatment (without herbicide). The experiment was performed twice (first in Piracicaba -SP then Palotina -PR) in greenhouse with different corn hybrids. Several variables related to the performance were analysed such as height measurements, stem diameter, chlorophyll index, fresh and dry shoot, root dry mass. The results showed that nicosulfuron should be positioned cautiously in new RR2 corn hybrids, as it may damage the development of the plant.

Post-emergent applications of isolated and combined herbicides on corn culture with cp4-epsps and pat genes

“…Studies have found that the initial growth of crops can be affected (Albrecht et al, 2017), by the early accumulation of Aminomethylphosphonic acid (Reddy et al, 2009) in treatments containing glyphosate (e.g., T5 and T8) or by the accumulation of glufosinate-ammonium and acetyl-glufosinate in the first hours following the application (Everman et al, 2009) in treatments containing glufosinateammonium (e.g., T7 and T8). However, we found that T5 and T8, which contained glyphosate and glufosinate-ammonium, respectively, did not affect the initial growth of the crops.…”

“…ha −1 ) were applied to corn. Various studies in the past have found that RR corn has a high tolerance and low phytotoxicity for the glyphosate herbicide (Albrecht et al, 2017;Nurse et al, 2006;Norsworthy and Frederick, 2005;Armel et al, 2003).…”